固定式海洋平台火炬臂结构拖航疲劳分析

为解决传统火炬臂不适用于海上整体拖航工况的问题,针对导管架固定式平台上部火炬臂结构,建立火炬臂整体拖航疲劳分析方法,设计一种适用于海上整体拖航的新型火炬臂连接形式。采用SACS软件建立平台上部组块带火炬臂整体有限元模型,分别对传统火炬臂结构和新型火炬臂结构进行整体拖航工况下的疲劳计算。提出最大疲劳损伤占比指标,从拖航疲劳损伤程度和最大疲劳损伤节点数目两个角度对新型火炬臂进行局部结构优化。结果表明:新型火炬臂斜撑的增设可有效改善火炬臂主弦杆的受力且大幅提高火炬臂的整体刚度,使原拖航疲劳损伤不满足规范要求的构件满足要求,为火炬臂海上整体拖航提供可行的技术和方案。

Towing Fatigue Analysis of Flare Boom for Fixed Offshore Platform

The fatigue analysis method is established and a new connection of flare boom to jacket platforms is proposed because the traditional flare boom is not suitable for overall towing at sea. The finite element of topside structure integrated with flare boom is built by SACS and the towing fatigue calculations of both traditional and new type of flare booms under overall towing condition are conducted. The maximum towing fatigue damage ratio is introduced, and new flare boom is optimized according to the maximum value of towing fatigue damage and the number of tubular joints of maximum fatigue damage. The results show that the diagonal braces of new flare boom not only effectively improve stress condition of main brace but also greatly improve integral rigidity. Towing fatigue damage of all hot points in new flare boom meet the fatigue specification. The research achievements provide a feasible solution for flare boom under the overall towing condition.